Difference between revisions of "MAX7219X4"

From Land Boards Wiki
Jump to navigation Jump to search
Line 92: Line 92:
 
* [https://docs.circuitpython.org/projects/max7219/en/latest/api.html#adafruit_max7219.max7219.ChainableMAX7219 adafruit_max7219.max7219.ChainableMAX7219 Docs page]
 
* [https://docs.circuitpython.org/projects/max7219/en/latest/api.html#adafruit_max7219.max7219.ChainableMAX7219 adafruit_max7219.max7219.ChainableMAX7219 Docs page]
 
<pre>
 
<pre>
class ChainableMAX7219(MAX7219):
+
classadafruit_max7219.max7219.ChainableMAX7219(width: int, height: int, spi: SPI, cs: DigitalInOut, *, baudrate: int = 8000000, polarity: int = 0, phase: int = 0):
 
     """
 
     """
 
     Daisy Chainable MAX7219 - driver for cascading displays based on max7219 chip_select
 
     Daisy Chainable MAX7219 - driver for cascading displays based on max7219 chip_select

Revision as of 15:10, 3 August 2022

Tindie-mediums.png


MAX8219X4 P18496 720PX.jpg

Features

  • (4) MAX7219 8 digits, 7 Segment display modules
  • 32 digits
    • 4 rows
    • 8 digits per row
  • Can display decimal, hex values, some text values
  • Each display has 8 of 7 segment LED displays
  • "Blue" card
  • 3.3V interface operation
    • 3.3V to 5V Level shifter
  • Requires both 3.3V and 5V power supplies
  • 8 pin connector
  • 95x95mm ODAS form factor
  • (4) 6-32 mounting holes

MAX7912 8 Digs 001.jpg

Connectors

MAX7219X4 Rev2 CAD.PNG

J1 Connector

  • 3.3V signal level
  • 5V power to LEDs
  • 1x8 right angle header mounted on rear of card
  1. GND
  2. GND
  3. DOUT
  4. CLK
  5. CS
  6. DIN
  7. +3.3V
  8. +5V

J2 (Rev 2 and higher)

  1. +5V
  2. DIN
  3. CS
  4. CLK
  5. DOUT
  6. GND

Programming

Arduino Programming

Arduino Drivers

Arduino Example Code

LBMAX7219X4_ADDR
  • LBMAX7219X4_ADDR
    • void writeHexDigit(uint8_t rowVal, uint8_t colVal, uint8_t digitVal) - Write Hexadecimal digit to location
    • 8 columns, 4 rows
    • rowVal = 0 is top row in display
    • colVal = 0 = left character
LBMAX7219X4
  • LBMAX7219X4
    • Displays Land-Boards channel intro video across the LEDs on 4 rows of 8-digits MAX7219X4 card
    • "LAND-" (first line)
    • "BOARDS" (second line)
    • "PRESENTS" (third line)
    • "CARDS...", "AND CODE" (4th line)

CircuitPython Programming

classadafruit_max7219.max7219.ChainableMAX7219(width: int, height: int, spi: SPI, cs: DigitalInOut, *, baudrate: int = 8000000, polarity: int = 0, phase: int = 0):
    """
    Daisy Chainable MAX7219 - driver for cascading displays based on max7219 chip_select

    :param int width: the number of pixels wide
    :param int height: the number of pixels high
    :param ~busio.SPI spi: an spi busio or spi bitbangio object
    :param ~digitalio.DigitalInOut chip_select: digital in/out to use as chip select signal
    :param int baudrate: for SPIDevice baudrate (default 8000000)
    :param int polarity: for SPIDevice polarity (default 0)
    :param int phase: for SPIDevice phase (default 0)
    """

VHDL Code

instance: MAX7219
    generic map(
            devices => 2,
            intensity => (16#1#, 16#3#)
        )
    port map (
            clk => clock,
            data_vector => x"FEDCBA9876543210",
            clk_out => MAX7219_CLK,
            data_out => MAX7219_DATA,
            load_out => MAX7219_LOAD,
            reset_n => globalResetN
        );

Test

  • Test single 8-digit modules
  • Test MAX7219X4 card with (4) 8-digit modules

Test Single MAX7219 Modules

SensorShield P1080453-720px.JPG

SenShld Desc MAX J1 Color
VCC VCC 1 RED
GND GND 2 BLK
D12 DATAIN 3 WHT
D10 CS 4 BRN
D11 CLK 5 YEL

Test MAX7219X4 Card

MAX7219X4 TEST-720PX.png

Signal AiB MAX7219X4 Signal Color
GND J5-25 J1-1 GND BLK
D10 J5-21 J1-5 CS WHT
D11 J5-19 J1-4 CLK YEL
D12 J5-17 J1-6 DIN BLU
+3.3V J5-1 J1-7 +3.3V RED
VFILT J9-1 J1-8 5V ORG

"Red" Modules

  • Incompatible pinouts
    • Do not work with this card
    • Flipped from blue modules

RedModule Overall P1080454-720px.jpg

RedModile Left P1080456-720px.jpg

RedModule Right P1080455-720px.jpg

Mechanicals

MAX7912X4 MECHS.PNG

Revision History

Rev 2

  • Add 5V interface connector - J2
  • Card can be driven from one of the two interfaces
    • 5V interface does not require 3.3V

MAX7219 Front Rev2 3D.png

  1. +5V
  2. DIN
  3. CS
  4. CLK
  5. DOUT
  6. GND

Rev 1

  • Tested/works
  • Requires 3.3V power and signal levels
  • Requires 5V power

Assembly Sheet